static headspace (hs) dynamic headspace spray-and-trap (st) spme membrane inlet
Post on 23-Jan-2016
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DESCRIPTIONExtraction Methods. Static Headspace (HS) Dynamic Headspace Spray-and-Trap (ST) SPME Membrane Inlet. Purge-and-Trap. Purge-and-Trap Method. Advantage : More sensitive than HS. Drawback : 1. Foaming and slowness of the purging step - PowerPoint PPT Presentation
Static Headspace (HS) Dynamic Headspace Spray-and-Trap (ST) SPME Membrane InletPurge-and-TrapExtraction Methods
Advantage : More sensitive than HSDrawback : 1. Foaming and slowness of the purging step 2. Large sample volume and long purging time (10~30 min)
Experimental AimTo construct an automated ST-GC system for on-line determination of dissolved VOCs in water.
Carboxen 1000Carboxen 10031/16Micro-sorbent Trap
2. Amount of sample3. Amount of extraction gas that is sampled.Sensitivity of Mode A1. Sprying conditionA. Size of dropletB. Extraction gas flow rateC. Design of nozzleD. Introducing a limited amount of sample and extraction gasSensitivity of Mode A
Mode A VS. Mode BA
Analytical conditions for ST and PT
Recoveries of ST methodsRecovery =
DL, R.S.D, and R2 for BTEX
Chromatograms of ST-GC-ECDCHCl3CCl4CH2Br2CHCl=CCl2CHBrCl2CCl2=CCl2
Conclusion An automated spray-and-trap device was built in the laboratory.
The studied ST method was validated in comparison with classic PT: recoveries precision, and linearity.
The ST method shows a fast response to abrupt changes in sample quality, which makes it suitable for on-site monitoring of a water body.